There are costly and challenging methods of verifying interconnections between cabling and a plurality of devices, including but not limited to sensors and the like. Dynamic sensors are transducers that are used to measure dynamic motion or force. Transducers exist in a large variety of shapes and forms, but virtually all consist of two general components: 1) a mechanical structure designed such that the applied motion or force input causes an internal deflection proportional to that input; and 2) an electrical element that measures that deflection such that the electrical output of the sensor is proportional to the magnitude of the deflection. The transduction from deflection to an electrical parameter defines the generic term “transducers” for such devices.
The form of electrical output of a dynamic sensor can vary to include virtually any parameter that is electrically measurable. A common measurement is charge, which is the number of electrons displaced by a dynamic event. However, the measurement might also be the voltage i.e., the electric field strength that caused those electrons to be displaced; the capacitance i.e., the ratio of charge to voltage; the current i.e., the rate of electron flow; the impedance or resistance i.e., the ratio of voltage to current, and so on.
As a non-limiting example, the basic design of a sensor consists of a thin plate of piezoelectric (“PE”) material clamped between a base and a mass. The mass serves as the inertial component. When the mounting surface that the base is attached to is accelerated, the inertial mass is also accelerated and results in a force that causes the PE material to deform. This PE property induces electrons to gather on one side of the plate. Electrodes attached to the appropriate surfaces of the plate lead to the electrical cable of the transducer, which communicates the induced electrical variance.
One problem that needs to be overcome in the design of detectors is the shielding from unwanted electrons that can be induced from myriad of external sources. For example, unwanted electrons may be manufactured from external electrical fields or from the rubbing of insulators in the electrical wires delivering the output to the data acquisition system. In order to overcome this problem, the prior art teaches specialized electronics and shielding techniques to reduce the errors caused by such external noise sources. One technique is using a circuit to perform an impedance conversion, internal to the sensor, which translates the quantity of electrons to a voltage level. Once the appropriate voltage is determined, the circuitry floods the output with sufficient electrons, increases the current, to maintain the voltage level while making the undesirable electrons induced by external sources insignificant. This circuitry may be referred to as an amplifier. These sensors along with their amplifier circuits are made by multiple manufacturers under many trademarks (e.g. ICP®, ISOTRON®, DELTATRON®), but can all be grouped under the term Integral Electronic Piezo Electric (“IEPE”).
The IEPE may be used in numerous different arenas. For example, the IEPE can be used in the industrial, environmental, military, and aviation fields. It can also be used for device monitoring, environmental monitoring, measuring experiments, seismic monitoring, conditional based machinery monitoring, vibration based alarming, shock detection, intruder deflection, infrastructure monitoring, and loose part detection, to name a few.
IEPE devices use two wires for their output. The first wire is the actual output which carries the additional current and the second wire is ground. The source of power for an IEPE device is a constant current thus, the output of the IEPE device, which represents the time-varying dynamic input to the transducer, takes the form of an analogously time-varying voltage. The time varying voltage component is in addition to the static voltage operating point of the IEPE circuit. The IEPE circuitry design has been extensively used in the industry for a number of reasons including its advantages in reduced noise, reduced cable costs, simplicity of associated external conditioning, and so on.
One characteristic of IEPE devices is that the static voltage operating point does not vary analogously to the parameter to be measured, even if that parameter has significant static value. The output of interest for IEPE devices is the alternating current (AC) (time varying) voltage signal riding on top of the static or “DC” operating point. The AC portion of the output signal does vary analogously with the input being measured.
Regardless of the type of sensor or its output signal, more often than not, numerous sensors may be used to monitor the performance, status or condition of a simple or complex structure or piece of equipment. Sometimes hundreds or even thousands of sensors may be used. Each sensor must be properly electrically connected to the equipment sensing the signal. The sensing equipment may be located far away, and each sensor may be connected through a cable with tens or hundreds of wires. If the sensor is connected to the wrong set of wires, then its output will appear on the wrong channel at the sensing equipment.
In addition to the sensors needing to be wired up to the cable correctly, the other end of the cable may not have a connector and may also need to be wired. Again, if the cable is wired to the sensing equipment incorrectly, the readings will be corrupted. In addition to the physical wiring, any software used within the sensing equipment to manage the various different sensor channels must also be configured correctly. All of these connections must be verified so that when a sensor displays an anomalous reading during use, the operator can be assured that the sensor showing that reading is in fact the sensor located in the physical location the operator thinks it is. Moreover, the operator may want to verify that the sensor is working correctly and the reading is not just from a malfunction of the sensor. All of this creates a verification nightmare.
Accordingly, there is a need to provide a mechanism for verifying the connections of multiple channels coming into a matrix of locations so that an operator can be assured that the sensor showing the measured reading is in fact the sensor located in the physical location he believes it to be. There is a further need to ease the interconnection verification between a plurality of cables and a plurality of sensors. In addition, there is a need to provide for a low cost mechanism to couple a plurality of channels coming into a matrix of locations.